Gas blast electric circuit breaker



, 1941- w. E. PAUL GAS BLAST ELECTRIC CIRCUIT BREAKER Filed Sept. 28,1940 Inventor: William E.Paul

. His Attorne Patented Aug. 19 1941 FFICE GAS nmsr anac'rarc cmourrBREAKER 7 William E. Paul, Schenectady, N. Y.,-assignor to GeneralElectric New York Company, a corporation of Application September 28,I940, Serial No. 358,847 4 Claims. (Clzoo-14s) My invention relates togas blast electric circuit breakers, and has for its principal objectthe provision of an improved gas blast circuit breaker having a largeeffective are cooling-area completely surrounding the arc forinterrupting large power currents. A further object of my invention isan improved diverging radial blast circuit breaker arranged to force thearc into surrounding arc extinguishing structure.

My invention will be more fully set forth in the following descriptionreferring to the accompanying drawing, and the features of novelty whichcharacterize my invention will be pointed out with particularity in theclaims annexed to and forming a part of thisspeciflcation.

Referring to the drawing, Fig.1 is a partly diagrammatic illustration ofan electric circuit breaker embodying the present invention includingcontrol means connected in an electric power circuit, Fig. 2 is anelevational sectional view of the gas blast circuit breaker shown inFig. l'-, and Fig. 3 is an elevational sectio along the line 3-3 of Fig.2.

Referring generally to Fig. 1, the gas blast circuit breaker indicatedat l is connected through its contact structure, hereinafter described,in series with an electric powercircuit 2, the terminals of the breakerbeing indicated 7 at 3 and 4. When an overload or short circuit occurson the power line, the contact structure air or gas pressure from asource indicated at! -10 spacers in the design illustrated mayconveniently be formedas U-shape so as to extend also between the plates19 along the vertical sides. The plates and spacers are provided withaligned apertures at the lower part of the casing to form a lateralpassage 2| communicating with the nal view taken v I pressure supplyconduit 5, the lateral passage 2i in turn communicating with verticalpassages 22 formed at opposite ends of the breaker casing leading to thecontact operating pistons l2 and The plates I! are also provided withaligned apertures 23 through which the contacts 9 and I0 operate. Itwill therefore be apparent that an are drawn between the contacts 0 andI0 2.5 will be completely surrounded by are extinguishin response tooperation of the valve 6. The- -valve control can beaccomplished in anysuitable manri r, such as by a current transformer l ,connecte to the,valve operating solenoid I. In addition to opening the contactstructure, the

ing baiiies or barriers defining radially diverging venting passages 24.

The operation of the circuit breaker is as 3 follows: Let it be assumedthat the breaker is in the closed circuit ppsition shown wherein thecontacts are biased into engagement by their respective closing springs25 and 26, and the. the control means at l and I call for a circuitopening operation. Immediately upon opening .of the valve i,-gas underpressure enters the gas under'pressure creates an arc'ex'tinguishingblast.

Referring more particularly to Fig. 2; the relatively movable contactstructure comprises a pair of tubular contacts 9 and Ill arranged toengage in butt contact at H. Each contact is connected to an operatingpiston, the pistons i2. and I3 respectively being guided forlongitudinal reciprocal movement in the cylinders I4 and; IS. Thecontacts are also provided with conducting extensions i6 and I1including the breaker terminals 3 and 4 which are guided in the ends ofthe cylinders I4 and i5, respectively.

The circuit breaker housing comprises an insulating casing l8 that maybe open at both lateral ends and also at the upper end. In the presentinstance the breaker casing, which is particularly designed-for highvoltage, is open passages 2| and 22 in the circuit'breaker so as to actdirectly on the pistons i2 and I3. The pistons are thereupon projectedat high speed into their cylinders causing rapid separation of 40 thecontacts 3 and Ill. At the same time, gas

under pressure entering the ports 12' and i3 of the tubular contactsflows through the tubular contacts toward the point ofcontact'separation. The resulting gas blast from both contacts acts frombehind the arc and serves to force it radially into the surrounding arcextinguishing structure defined by the plates is. a

In view of the fact that the arc must form slightly greater than that oftially in contact with are extinguishing structure immediately upon itsformation. .Also, the'blast which mushrooms from the ends of the tubularcontacts as illustrated by Fig. 3 necessarily traverses the arcregardless of its position between the contacts forcing it into theradially diverging passages 24. Stop and buffer means for the pistons l2and I3 respectively are also preferably providedin the cylinders 14 and15 comprising the spring enclosing sleeves l4 and I5 seated at rubberrings l4" and I5".

The contacts are now well separated and the blast continues as long asthe valve 8 is held open in response to continuance of the fault.Although I have not in the interest of simplicity disclosed additionalmeans for opening the circuit so that the arcing contacts can return toclosed position after interruption of the arc since this forms no partof my present invention, it will be apparent that a disconnecting switchcan be connected in series with the power line 2 as indicated at 21 soas to be opened after interruption of arcing By reason of the large arccooling area extending radially from the arc in all directions, thelarge volume of highly heated arc gases accompanying heavy currentinterruptions, as well as the arc-itself, are effectively cooled by thelarge passage area of the radially diverging passages between the platesI9. Theradially diverging passages extending in all directions laterallyof the are also aid in reducing back pressure to the gas blast byeffectively dissipating the arc gases flowing into the extinguishingstructure.

It should be understood that my invention, is not limited to specificdetails of construction and arrangement thereof herein illustrated, andthat changes and modifications may occur to one skilled in the artwithout departing from the spirit of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. An electric circuit breaker of the gas blast type comprisingrelatively movable tubular contacts for directing a gas blast inopposite directions substantially axially of said contacts so as to meetand traverse the are at the point of contact separation, and arcextinguishing baiiie structure composed of insulating material arrangedcompletely to surround the aforesaid arc and to form radially divergingblast ventin passages leading from the exhaust ends of said tubularcontacts.

i 2. An electric circuit breaker of the gas blast type comprisingrelatively movable tubular contacts for directing a gas blast inopposite directions substantially axially of said contacts so as tomushroom from the coacting ends of said contacts and traverse the are atthe point of contactseparation, and arc extinguishing insulating. plateshaving alined apertures for said contacts arranged in spaced relationtransversely of said are so as completely to surround the aforesaid arcand to form radially diverging blast venting passages leading from theregion of said arc.

3. An electric circuit breaker of the gas blast type comprisingrelatively movable tubular contacts including means for directing a gasblast in opposite directions substantially axially of said contacts soas to meet and traverse the are at the point of contact separation,means for causing separation of said contacts by and in accordance withsaid gas blast, and are extinguishing structure including spacedinsulating plates having alined apertures for said contacts arrangedcompletely to surround the aforesaid arc and to form radially divergingblast venting passages leading from the region of said arc.

4. An electric circuit breaker of the gas blast type comprisingrelatively movable tubular contacts for'directing a gas blast inopposite threetions substantially axially of said contacts so as tomushroom from the contact-making ends of said tubular contacts andtraverse the are at the point of contact separation, arc extinguishinginsulating structure through which said tubular contacts operate inclose proximity arranged completely to surround the aforesaid arc and toform a plurality of spaced radially diverging blast venting passagesleading from the contact passages, means for connecting both saidtubular contacts with a source of blast pressure, and piston means forcausing separation of said contacts in response to blast pressure.

WILLIAM E. PAUL.

